In China it is understood that red color is used to indicate STOP because it has the greatest wavelength and is therefore more visible in inclement weather.
In addition, color code for traffic light is fixed by international convention and it’s not like China can choose whatever it wants.
My point is, culture has nothing to do with the choice of stop light color in China
That's exactly my point as well. The article mentioned that the association between red and "bad" stuff (stop, error, etc.) is cross-cultural. Someone replied vehemently denying that, but the fact is that red={stop, error, bad, ...} is a long-standing international convention that does supersede regional cultural effects.
China can choose whatever they want, but don't.
Many countries have not signed the Vienna Convention on Road Signs and Signals. For example China, Japan and the United States have not signed the convention.
Japan is a good example: "It is a near universal constant when driving: red means stop, and green means go. So fundamental is this dynamic that it is codified in international law under the Vienna Convention on Road Signs and Signals, which has been ratified by 74 countries. Why, then, does Japan — not a signatory to the Convention —seem to buck the trend with its blue/green traffic signals?" https://www.atlasobscura.com/articles/japan-green-traffic-li...